In recent years, domestic robots such as care robots or housework supporting robots are being actively developed. Further, as to industrial robots, robots that cooperate with people are being actively developed due to spread of cell production plant or the like.
As one example of robots that cooperate with people, there are proposed robots which are operated according to a manipulation force from a person by impedance control so as to realize power assist.
In a task that involves contact between a gripped object and an external environment in power assist robots that use impedance control, there is a problem that it is difficult for a person manipulating the robot to grasp the contact state.
In order to solve such a problem, Patent Literature 1 discloses a technique for detecting the contact between a gripped object and an external environment by a force sensor, and making control so that the detected external force acts upon a manipulating unit, so as to make the generated contact stable without vibration (see Patent Literature 1).